Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 182 insertions, 0 deletions

diff --git a/accessible/base/nsTextEquivUtils.h b/accessible/base/nsTextEquivUtils.h
new file mode 100644
index 0000000000..90f8a56a54
--- /dev/null
+++ b/accessible/base/nsTextEquivUtils.h
@@ -0,0 +1,182 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:expandtab:shiftwidth=2:tabstop=2:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef _nsTextEquivUtils_H_
+#define _nsTextEquivUtils_H_
+
+#include "mozilla/a11y/Accessible.h"
+#include "Role.h"
+
+class nsIContent;
+
+namespace mozilla {
+namespace a11y {
+class LocalAccessible;
+}
+}  // namespace mozilla
+
+/**
+ * Text equivalent computation rules (see nsTextEquivUtils::gRoleToNameRulesMap)
+ */
+enum ETextEquivRule {
+  // No rule.
+  eNoNameRule = 0x00,
+
+  // Walk into subtree only if the currently navigated accessible is not root
+  // accessible (i.e. if the accessible is part of text equivalent computation).
+  eNameFromSubtreeIfReqRule = 0x01,
+
+  // Text equivalent computation from subtree is allowed.
+  eNameFromSubtreeRule = 0x03,
+
+  // The accessible allows to append its value to text equivalent.
+  // XXX: This is temporary solution. Once we move accessible value of links
+  // and linkable accessibles to MSAA part we can remove this.
+  eNameFromValueRule = 0x04
+};
+
+/**
+ * The class provides utils methods to compute the accessible name and
+ * description.
+ */
+class nsTextEquivUtils {
+ public:
+  typedef mozilla::a11y::LocalAccessible LocalAccessible;
+  typedef mozilla::a11y::Accessible Accessible;
+
+  /**
+   * Determines if the accessible has a given name rule.
+   *
+   * @param aAccessible [in] the given accessible
+   * @param aRule       [in] a given name rule
+   * @return true if the accessible has the rule
+   */
+  static inline bool HasNameRule(Accessible* aAccessible,
+                                 ETextEquivRule aRule) {
+    return (GetRoleRule(aAccessible->Role()) & aRule) == aRule;
+  }
+
+  /**
+   * Calculates the name from accessible subtree if allowed.
+   *
+   * @param aAccessible [in] the given accessible
+   * @param aName       [out] accessible name
+   */
+  static nsresult GetNameFromSubtree(const LocalAccessible* aAccessible,
+                                     nsAString& aName);
+
+  /**
+   * Calculates text equivalent from the subtree. Similar to GetNameFromSubtree.
+   * However it returns not empty result for things like HTML p.
+   */
+  static void GetTextEquivFromSubtree(const Accessible* aAccessible,
+                                      nsString& aTextEquiv) {
+    aTextEquiv.Truncate();
+
+    AppendFromAccessibleChildren(aAccessible, &aTextEquiv);
+    aTextEquiv.CompressWhitespace();
+  }
+
+  /**
+   * Calculates text equivalent for the given accessible from its IDRefs
+   * attribute (like aria-labelledby or aria-describedby).
+   *
+   * @param aAccessible  [in] the accessible text equivalent is computed for
+   * @param aIDRefsAttr  [in] IDRefs attribute on DOM node of the accessible
+   * @param aTextEquiv   [out] result text equivalent
+   */
+  static nsresult GetTextEquivFromIDRefs(const LocalAccessible* aAccessible,
+                                         nsAtom* aIDRefsAttr,
+                                         nsAString& aTextEquiv);
+
+  /**
+   * Calculates the text equivalent from the given content and its subtree if
+   * allowed and appends it to the given string.
+   *
+   * @param aInitiatorAcc  [in] the accessible text equivalent is computed for
+   *                       in the end (root accessible of text equivalent
+   *                       calculation recursion)
+   * @param aContent       [in] the given content the text equivalent is
+   *                       computed from
+   * @param aString        [in, out] the string
+   */
+  static nsresult AppendTextEquivFromContent(
+      const LocalAccessible* aInitiatorAcc, nsIContent* aContent,
+      nsAString* aString);
+
+  /**
+   * Calculates the text equivalent from the given text content (may be text
+   * node or html:br) and appends it to the given string.
+   *
+   * @param aContent       [in] the text content
+   * @param aString        [in, out] the string
+   */
+  static nsresult AppendTextEquivFromTextContent(nsIContent* aContent,
+                                                 nsAString* aString);
+
+  /**
+   * Iterates DOM children and calculates text equivalent from each child node.
+   * Then, appends found text to the given string.
+   *
+   * @param aContent      [in] the node to fetch DOM children from
+   * @param aString       [in, out] the string
+   */
+  static nsresult AppendFromDOMChildren(nsIContent* aContent,
+                                        nsAString* aString);
+
+ private:
+  /**
+   * Iterates accessible children and calculates text equivalent from each
+   * child.
+   */
+  static nsresult AppendFromAccessibleChildren(const Accessible* aAccessible,
+                                               nsAString* aString);
+
+  /**
+   * Calculates text equivalent from the given accessible and its subtree if
+   * allowed.
+   */
+  static nsresult AppendFromAccessible(Accessible* aAccessible,
+                                       nsAString* aString);
+
+  /**
+   * Calculates text equivalent from the value of given accessible.
+   */
+  static nsresult AppendFromValue(Accessible* aAccessible, nsAString* aString);
+
+  /**
+   * Calculates text equivalent from the given DOM node and its subtree if
+   * allowed.
+   */
+  static nsresult AppendFromDOMNode(nsIContent* aContent, nsAString* aString);
+
+  /**
+   * Concatenates strings and appends space between them. Returns true if
+   * text equivalent string was appended.
+   */
+  static bool AppendString(nsAString* aString,
+                           const nsAString& aTextEquivalent);
+
+  /**
+   * Returns the rule (constant of ETextEquivRule) for a given role.
+   */
+  static uint32_t GetRoleRule(mozilla::a11y::roles::Role aRole);
+
+  /**
+   * Returns true if a given accessible should be included when calculating
+   * the text equivalent for the initiator's subtree.
+   */
+  static bool ShouldIncludeInSubtreeCalculation(Accessible* aAccessible);
+
+  /**
+   * Returns true if a given accessible is a text leaf containing only
+   * whitespace.
+   */
+  static bool IsWhitespaceLeaf(Accessible* aAccessible);
+};
+
+#endif